[Blob] BlobReader class & tests, and removal of all redundant reading.

storage/browser/blob/blob_storage_context.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "storage/browser/blob/blob_storage_context.h"
 
 #include <algorithm>
 #include <limits>
 
 #include "base/bind.h"
@@ skipping 59 matching lines @@
 scoped_ptr<BlobDataHandle> BlobStorageContext::GetBlobDataFromUUID(
     const std::string& uuid) {
   scoped_ptr<BlobDataHandle> result;
   BlobMap::iterator found = blob_map_.find(uuid);
   if (found == blob_map_.end())
     return result.Pass();
   auto* entry = found->second;
   if (entry->flags & EXCEEDED_MEMORY)
     return result.Pass();
   DCHECK(!entry->IsBeingBuilt());
-  result.reset(
-      new BlobDataHandle(uuid, this,
-                         base::ThreadTaskRunnerHandle::Get().get()));
+  result.reset(new BlobDataHandle(uuid, entry->data->content_type(),
+                                  entry->data->content_disposition(), this,
+                                  base::ThreadTaskRunnerHandle::Get().get()));
   return result.Pass();
 }
 
 scoped_ptr<BlobDataHandle> BlobStorageContext::GetBlobDataFromPublicURL(
     const GURL& url) {
   BlobURLMap::iterator found =
       public_blob_urls_.find(BlobUrlHasRef(url) ? ClearBlobUrlRef(url) : url);
   if (found == public_blob_urls_.end())
     return scoped_ptr<BlobDataHandle>();
   return GetBlobDataFromUUID(found->second);
@@ skipping 398 matching lines @@
   if (found == blob_map_.end())
     return false;
   return found->second->IsBeingBuilt();
 }
 
 bool BlobStorageContext::IsUrlRegistered(const GURL& blob_url) {
   return public_blob_urls_.find(blob_url) != public_blob_urls_.end();
 }
 
 }  // namespace storage